I'm at a bit of a loss with what to do with Hermione without Ron around. (If anyone wants to pick up Ron, I would LOVE YOU FOREVER ZOMGLOLWTFBBQ)
So I'm going to have Hermione be a bit withdrawn, and assume that she and Ron are about to hit an off-again point in their relationship. I figure if/when we get a new Ron, we can retcon, or re-write their history to make it fit both of our ideas about their relationship. My Hermione backstory is completely adaptable, and admitting a new Ron shouldn't be a problem at all.
That being said, Harry/Weasleys (and anyone at Easter or George's birthday party) can totally note that Hermione and Ron are at odds. I imagine they probably got into a row at the end of George's birthday party, and Hermione left in a bit of a huff.